


Möbius

by Isobel_Morgan



Category: Doctor Who (2005)
Language: English
Status: Completed
Published: 2021-01-03
Updated: 2021-01-03
Packaged: 2021-03-13 10:13:55
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,465
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28526790
Author URL: https://archiveofourown.org/users/Isobel_Morgan/pseuds/Isobel_Morgan
Summary: Donna asks the Doctor to find her some ancient ruins, like the ones Indiana Jones might explore, but alien, and of course they promptly get stuck in an impossible trap.(Alt version of chapters 1-2 of "A Future in Ruins")





	Möbius

**Author's Note:**

> This was my entry for the Big Finish: Short Trips competition (which didn't win, obviously, but I hope you like it anyway).
> 
> I originally wrote this story for Thirteen and her new companion (see A Future In Ruins), then adapted and shortened it for the competition.

**Möbius**

"D'you know what I really wanna do?" Donna said.

The Doctor looked up from the TARDIS console.

"What?"

"You know Indiana Jones?"

"Um, no. Who's he?"

"You don't know who Indiana Jones is? I thought everyone knew that, even space men from another planet?"

"Donna, the Universe is a big place. Even in over 900 years, there's bound to be a few people I haven't met yet."

"They're films, you plank. He's an archaeologist who explores ancient ruins and finds treasure. Can we do that? Find some huge ancient ruins, alien ones?"

"Why would you want to do that, when I can take you to ancient civilisations when they still stand?" the Doctor asked. "What can you learn from ruins that you can't learn from the people who lived there?"

"Because that can get… complicated." Donna went momentarily serious, remembering Pompeii.

"Besides, not knowing's half the fun? Indiana Jones always goes poking about where he's not supposed to, I thought that'd be right up your street."

"Yes, but-" the Doctor indicated himself. "Time traveller? Out of all of time and space, you want to go somewhere there aren't any people?"

Donna rolled her eyes.

"I'm not asking to live there! Just have a look round, see if there's any giant rolling boulders set up as a trap-"

"A what?" The Doctor couldn't understand Donna's enthusiasm for what she was describing at all.

"Oh, honestly. All of space and time, and you never found time to go to the cinema?"

"I was there when cinema was _invented_ ," he began but Donna wasn't really listening.

"He fights Nazis, when he isn't leaping into ancient temples and stuff. And he usually wears short sleeves, which really make the most of his biceps-"

"All right, all right, all right!" The Doctor interrupted. "If I find you some ancient alien ruins, will you stop talking about him?"

"Promising nothing!" Donna replied, with delight.

The Doctor thought quickly.

"How about Rhyolae? It's a planet in the Kjadi system."

The Doctor input the coordinates, and on screen it showed a small green planet within a spiral galaxy.

"For thousands of years, there was a civilisation called the Isenal. Built these huge temples, and their cities grew up around them. Most of them still stand, though they're in ruins. The modern culture on Rhyolae have this organisation, the Keepers, dedicated to preserving them."

"Have you been before?" Donna asked.

"Not since the Isenal civilisation ended. Like I said, best way to see something is when it's alive and kicking."

Donna grinned.

"I'll fetch my hat and my whip."

The Doctor blinked.

"Just what are you planning on doing when we get there?"

"Watch the films!" Donna shouted over her shoulder, as she ran off into the TARDIS, seeking out the wardrobe.

* * *

To his immense relief, she didn't come back wielding a whip, but she was wearing a sun hat, and practical clothing - trousers, a long-sleeved top and sturdy looking trainers. The Doctor put his coat on.

"Ready?" he asked.

Opening the doors, they found themselves right in the middle of the ruins.

"Wow!" Donna was ecstatic. "This is brilliant!"

"See that?" the Doctor pointed at the enormous stepped pyramid before them.

"That's the Elevation Temple, the most important building in the city, where they held all their rituals. This courtyard-y bit we're in is called the Confluence."

The walls were high, but any roofs were long gone, leaving the ruins open to the lilac sky. The jungle had moved in, creepers making long arms inside the structures and wrapping themselves around ceiling columns that now held up nothing. The orange sun was high in the sky, and it was uncomfortably warm, but very beautiful.

"This goes for every time we're exploring new places," the Doctor said. "But watch where you step, and don't touch anything."

"I know that," Donna replied. "Ancient ruins are always booby trapped in films. Sometimes it's just to stop you stealing any treasure, but some you have to work out puzzles just to get through them."

"I don't know about puzzles, but The Keepers have spent generations deterring tomb robbers, and anyone who wants to study the ruins is carefully vetted."

"Good job I've got a friend with a spaceship, then."

Keeping a careful eye where they stepped, they started to explore. Donna wanted to run about in excitement, but she also wanted to have a proper look round before any poison darts got fired, or the floor started falling away beneath her.

She was drawn to the bright flowers growing from the vines along the wall beside them. Each bloom was the size of her own face, the petals shades of pink and purple and the pollen in the centre a vivid yellow.

"These are gorgeous!"

The Doctor glanced over.

"Um, I wouldn't get too close, if I were you."

"Why?"

"Because they're Venandi blooms. They hunt by entangling prey in their creepers."

"Hunt?!"

Donna snatched her hand back, and sought out something a little safer.

There was a huge stone column set in the centre of the Confluence, inscribed with pictograms. The telepathic circuits took longer to translate the written word, but as Donna read through them, she realised these were stories of how the temple came to be built, what deities they were for. And then she recognised one glyph.

"Doctor?"

"Hmm?"

"Why is there a picture of the TARDIS in the middle of this column?"

The Doctor joined her.

"Oh."

" 'Oh', he says. When you told me you'd been here before, you didn't mention that they think you're a god?"

The Doctor read through the story.

"That's not _quite_ what happened. Bit of a misunderstanding, really. All I did was help them out with some of the city plans, saw off a rampaging horde of Lanessi beasts…"

He examined the figures next to the TARDIS glyph - a man in a hat with a long scarf, and a woman in a short dress, holding a knife.

"Leela was the one who got really involved with their society. Doubt she'd be happy about how they remember her, though; she had a bit of thing against worshipping false gods."

"Is travelling with you always gonna be like this?" Donna asked. "Go to an ancient city, you're a god. Meet aliens, you already know what they are. If we land in the middle of nowhere, is someone gonna recognise you?"

The Doctor grinned.

"Possibly."

"Tell me there isn't gonna be a huge statue of you inside the temple?"

"Probably not. The Isenal already had a pantheon of gods they worshipped long before I turned up."

"Did they keep lots of treasure? Gold idols, that sort of thing?"

"Why, are you planning on robbing this place?" the Doctor asked, eyebrows raising.

"Course not! What would I even do with a gold idol? I just wanna see if there's anything like that sitting about."

"Is that we he does? Your Indiana fellow?"

"Only to put them in museums, or stop Nazis from getting hold of them."

"Does that happen a lot? Nazis trying to rob tombs?"

"You're the man with a time machine. You tell me."

They wandered closer to the temple. There was no one else about, only a few lizard-like creatures skittering by, brightly coloured birds flitting through the sky, making weird cries.

They reached the foot of the steps, looking up.

"Is it safe to go in?" Donna asked.

"I don't know. They were pretty protective of their temples before, but that was thousands of years ago. They hadn't even started building this one then."

"Shall we have a look?"

"Carefully."

"And here I thought you were the sort of man who always goes running into trouble head first," Donna teased.

"That doesn't mean I'm looking to go falling in big holes full of sharp sticks, or pits full of snakes, if I can avoid it."

"Something you and Dr Jones have in common, then - don't like snakes."

"Martha?"

"Who?"

"Dr - nevermind."

They weren't far up the steps when they felt the first tremor.

"Doctor? Is that natural, or are we causing that?"

The Doctor paused, looking out across the ruins, where the pillars were visibly shaking.

"Not sure. Maybe we should-"

The quake suddenly got much stronger and the Doctor grabbed Donna's hand.

"Let's get back down. It could just be a tremor, but-"

"Good idea."

They hurried back down the steps and across the Confluence, the quake continuing to escalate, but before they could make it back inside the TARDIS, there was a sudden flash of bright light, and they both vanished.

* * *

The Doctor and Donna reappeared together, seemingly in the same place they'd left, skidding to a halt. The tremors stopped.

"What was that?" Donna asked.

"I think we triggered one of those booby traps you were talking about. Felt like… some kind of teleport maybe?"

"But we're in the same place. Aren't we?"

The Doctor turned a full circle, looking around.

"Notice anything different?"

Donna did the same.

"The temple's gone."

"So's the TARDIS." The Doctor pointed out the most pressing concern.

"So we got moved to a different part of the city? What sort of booby trap does that?"

"I'm not sure we're even in the same city."

The Doctor took out the sonic, but it refused to work.

"Hmm. Dampening field?"

He licked a finger, holding it up as if to test the wind.

"Yeah… some kind of suppression. Not just electronics. It feels… closed in."

"I feel that too," Donna replied. She looked up at the sky, which was the same shade of lilac, looked almost real, but not quite. It was cooler, the orange sun close to setting. There was a brightness, a shininess to everything, a veneer.

"Something in the air. Something not right."

"Like there's no one else around, not at all?" the Doctor replied, trying to put the sensation into words. "Like we're cut off, in a little bubble."

"Is this real, d'you think?"

"Not sure. Best to assume it's very real. The important question is, if this is a trap built to catch tomb robbers, then is it a prison, or is it likely to be lethal?"

Donna was uneasy.

"This never happened to Indiana Jones."

"On the other hand," the Doctor said, trying to be cheery. "If there was a way in, then there must be a way out. So let's have a look round, yeah?"

* * *

They went on.

And on.

And on.

"I know these ruins cover a lot of ground, but shouldn't they be a bit more varied?" the Doctor asked, pointing to a tall column. On closer inspection, it had the same carvings as the one by the temple, with the TARDIS glyph on.

"Is there more than one of those, or are we going round in circles?" Donna said.

"Good question. That'd be a pretty effective trap, if we're stuck in a loop."

"What about out there?" Donna pointed upwards. "Is there anything the other side of the wall?"

"Let's have a look."

The walls were high and solidly built, but the Doctor managed to get to the top, using the sturdiest creepers as hand and foot holds.

"Generally speaking, Venandi plants only hunt when they're in flower," he remarked. "Let's hope that's still the case inside this trap."

"Can you see anything?" Donna asked.

"Um, no. Literally nothing."

"What do you mean?"

"Just a grey nothing. Like we're in the middle of some sort of really thick mist."

He stood up on the top of the wall, and looked out, in all directions.

"Well, wherever we are, this section of the ruins is the only thing that exists."

He picked a loose stone off the top of the wall and dropped it on the far side, watching it vanish into the 'mist'. There was no sound of it hitting anything, so he threw another, further out into the nothing. Again, no sound, no impact.

"There's gravity, but I can't tell if it works properly out there." the Doctor said.

"I wonder…"

He gathered a few particularly long creepers that were bedded deeply into the ground at one end, and twisted them together to make a rope.

"Hopefully these ones are dormant," he muttered. "I'd rather not get eaten. Be a terribly embarrassing way to die."

He began to abseil down the far side of the wall. He paused as he got to the mist, reaching out to pass his hand through it.

"Weird. Nothing at all. Not cold, or damp, or anything. Like it's not there."

He slowly descended further, the mist swallowing him up.

"Doctor?" Donna called. "Are you all right?"

"Yeah. Though…" he trailed off, unnerving Donna. She climbed the wall after him, peering down through the mist.

"Doctor? Keep talking, I can't see you."

"I feel sort of… distant. It's harder to think… like the dampening field, but for a person… maybe this is the dampening field?"

His voice was faint, like he was very far away, or falling asleep.

"Hold on, I'm trying to see if there's a floor…"

But as he spoke, another tremor started. Donna grabbed the vine rope, dropping to her knees to steady herself.

"Doctor, do you feel that too?"

"There's a vibration through the vine-" His voice drifted up to her.

"It's getting really strong, more than before," she replied. "I think it's reacting to you."

Donna tried to maintain her grip on the vines, to use it to steady herself as well as keep in contact with the Doctor.

"I've reached the end of the rope. There's still nothing."

"Come back up!" Donna called. "It feels like the walls are going to fall down!"

She began to tug on the creepers, which suddenly felt much heavier than just the Doctor's weight.

"Wonder what'd happen if I let go?" the Doctor mused, somewhat dreamily.

Then the tremor turned to a violent quake, the vines snapped and they both fell.

* * *

Donna was thrown from the top of the wall, landing on the ground back inside the Confluence. Dazed, it took a moment for her to realise what had happened, scrambling to her feet.

"Doctor! Where are you?"

"Up here."

His voice sounded further away, and as Donna looked up, she realised why. Above her, in place of the lilac sky, was a reflection of the ruins she stood in. No, not a reflection, because there was the Doctor, upside down, waving at her.

"What? How-?"

Donna looked down at her feet, around at the ruins, then back up at the sky. Nope, still no sky. The walls reached up until they met the 'other' walls, enclosing the ruins - or what looked like the ruins.

"I don't understand."

"Well, for a start, there really is nothing on the other side, so we can't get out that way," the Doctor called to her. "When I fell, I landed here."

"But where are you?"

"Still in the trap, just a different spot. It's not just a loop; it's a Möbius strip."

"A what?"

"A two-dimensional compact manifold. A non orientable surface."

Donna heard the words, but was no more enlightened.

"You what?"

"Try throwing something up to me."

"How can I throw something up there?"

"Just try it."

Donna looked around. The end of the creeper they'd used as rope lay beside her so she picked up a section and threw it in the air, expecting it to come back down. But it didn't. Instead it continued up into the air, landing at the Doctor's feet, far above Donna's head, making her dizzy and disorientated.

"Are you upside down or am I?"

"Neither of us are…hang on. I'll show you. Wait there."

The Doctor jogged off along the path, to Donna's right, and disappeared from view.

After a while, he reappeared at the same level as Donna, the right way up again.

"I still don't understand."

"Basically, imagine a long thin strip, folded into a loop with a twist in it, like an infinity symbol. That's what we're standing on now, that's why we keep coming back to the same spot. It only has one surface."

Donna looked up, still utterly confused. She could still see the 'upside down', although it was fuzzy now the Doctor no longer stood there, the false sky showing through.

"I thought you said the TARDIS translates everything? Cos I don't speak gobbledygook and not a word of that made sense."

The Doctor sighed.

"You know what an infinity loop looks like?"

He sketched one in the air, a sideways figure eight.

"This trap is one of them?"

"An extra complicated one."

"And that means there isn't a way out?"

"Not that we can find by walking along. We'll just keep looping around."

"So can we-" Donna struggled to get her head around the concept. "Unroll it? Make it flat, so instead of a loop, it's just one side with two ends?"

"Nice idea, but I'm a bit stuck on the how." The Doctor took out the sonic, shook it, tried it again but got nothing.

He started thinking out loud, trying to figure it out.

"There shouldn't really be walls if this is a Möbius strip, it shouldn't have edges like that. If the loop is the only thing that exists, the walls must be part of the containment and that's why when I fell outside, it brought me back in. How did the Keepers build this?"

Donna wondered what was going on inside her friend's head. She knew she'd never be able to understand, but she could at least try and keep up.

"Is there a join, or something? Somewhere we could split it open?"

"Yes and no. Technically, no, because it's an infinite loop with only one side. We created a starting point for ourselves -" he pointed at the column with the TARDIS glyph "- so we can mark a full loop and recognise that we've covered all the ground there is. What we need to do is turn that into what you're talking about. Create a weak spot and break through, make it intersect with outside."

"Okay." Donna thought about this. "How?"

"No idea. If I could use the sonic… so what we really need to do is get rid of the dampening field first."

He jumped up and down a few times, testing the gravity.

"When we were at separate points of the trap, two perspectives existed together. There wasn't really an upside down, but we could see it that way. We need to split it again and test it out."

"Test what out?"

"When we were in two different places, we could see it as a loop, rather than flat. I might be able to use that to break us out, or at least to stop the loop keeping us inside."

"Not following a word, but okay? What do you need me to do?"

"Just stay here for a minute, and keep looking up."

While Donna did that, the Doctor scrambled up the wall again, and jumped 'out', disappearing into the mist. As Donna watched the sky, it flickered and vanished, replaced by the 'upside down' once more.

"So now… we both need to jump."

"You what? You want me to jump off a wall into nothing, so I can land in the sky?"

"It'll be okay, I promise!" he called down.

"Not if I break my neck, it won't!" Donna shouted back.

"Look, I'm sorry, Donna, but this might be the only way out. I don't know what's maintaining the loop, but it probably isn't designed to cope with us both jumping at the same time, from two different points."

"So… you're hoping that if we confuse it enough, it'll break?" Donna asked.

"Pretty much."

Donna sighed, and began to climb the wall.

 _'At least you're never bored, travelling with the Doctor,'_ she thought. _'Whatever happens, never bored.'_

* * *

The two of them stood on top of their section of wall, looking up at each other, seemingly upside down to the other but in fact on the same surface.

"Keep looking at me as you jump, if you can," the Doctor called. "When I say go-"

"If this goes wrong-" Donna shouted. "I'm gonna kill you!"

"Go!"

The Doctor and Donna jumped. Both vanished into the mist, landing on the ground at a different spot than the one they'd left.

"Look up!" the Doctor shouted, and suddenly it was like being inside an M.C Escher painting, as the loop tried to show four perspectives at the same time of something that only had one side. The Doctor tried the sonic again, and -

"Yes!"

The sky, which was currently other sections of ground, cracked open and the Doctor tried to get a foothold, now the dampening field was fritzing.

"Not the first time I've been stuck in something like this. Should be a piece of cake, unrolling a Möbius strip. Just need to make sure we're on the right side when it flattens out…"

He could do the calculations easily enough, but the sonic wasn't powerful enough to reach all points of the trap, so he focused on creating a weak point, from which he could cut the loop.

"Is it working?" Donna asked, getting to her feet. She wasn't entirely sure which way was up, as it looked like there were four 'ups', all looking down on the others and the ground didn't feel steady under her feet. She couldn't shake the idea that she could fall off the ground and into the sky. Not that there was any sky.

 _'This is more confusing than time travel,'_ she thought.

"Sort of?" the Doctor replied. " The Keepers weren't messing about when they built this trap."

"What does that mean?"

"It means… hang onto something!"

One final burst, which should break whatever was holding the loop together…

Everything expanded, like lungs filling with air, and the Doctor felt something shift, dimensionally. The mass, every property of the trap altering.

"What's happening?" Donna yelled.

Gravity felt wrong, like they were being pushed up and pulled down at the same time and they only just cancelled each other out, and a wind picked up out of nowhere, whipping around them.

"It's splitting in two!" The Doctor shouted back, continuing to try and fix the situation with the sonic. "Creating two mirror image Möbius strips. If they're joined together in a four dimensional space, it'll create a Klein bottle, and I don't think I can get us out of that."

"A what?"

"It's still a surface with one side, but where a Möbius strip has a boundary, a Klein bottle doesn't and it can't exist in three dimensional space without intersecting with itself."

This was not enlightening to Donna.

"Speak English!"

"It's… complicated."

"King of the understatement!"

"Think of it as a bottle with a long thin neck that bends back inside the body of the bottle."

"And?"

"And the inside and the outside are the same surface, like the Möbius strip. So it can't contain anything inside it, because the inside is also the outside?"

Donna groaned.

"This is worse than trying to understand how the TARDIS is bigger inside than out."

"It's actually more straightforward-"

"That doesn't help!"

 _'But there's an idea,'_ the Doctor thought. _'If there's one thing the TARDIS knows, it's dimensional engineering. And you'd need a hell of a dampening field to stop her.'_

He changed tack, and instead of trying to 'break' the loop, tried to connect with the ship, through the crack they'd made in the trap.

 _'Could really use a remote control, right about now,'_ he thought, but then he remembered how he'd once used the Huon particles inside Donna to bring the TARDIS to them. Those particles were long gone, but…

"Stay where you are, I'm coming to you!" he called, pelting off.

Donna rolled her eyes.

"Like I can tell where anywhere else is right now."

As the Doctor reappeared beside her, he grabbed her hand, there was a whirr of the sonic, a bright light, a noise like a balloon bursting, and Donna passed out.

* * *

Donna awoke with a start, hugely relieved to find herself back in the TARDIS.

"What happened?"

"I'm not actually sure," the Doctor replied, pushing buttons and flipping switches on the console. "I managed to use the artron energy in both of us to connect to the TARDIS and I tried to bring her inside the trap to rescue us."

"And?"

He frowned, ran to the doors and opened them. The TARDIS was in the same spot they'd left it. He could see the temple, and everything seemed to be fine. The Doctor came back in, grinning.

"And it looks like when the TARDIS materialised around us, she managed to bring the whole trap in too."

"What? "

"She moved the whole pocket dimension we were in, separated us from it and returned us here, then she took the whole thing, the Klein bottle and she put it away somewhere inside herself."

"How? No, wait, don't answer that."

"Not sure I fully understand it myself."

The Doctor went back to the console, pushing more buttons.

"But yep, there it is. Better close that section off, don't want anyone accidentally wandering in and getting stuck again, and I don't want it flipping and trapping the TARDIS inside it either."

The console beeped and trilled, and the Doctor pulled a conciliatory face.

"No, I know you wouldn't let that happen. I'm just saying-"

He was interrupted by a shrill noise, and held up his hands.

"All right, I'm sorry! Didn't mean to offend you."

He patted the console.

"You did brilliant. Thank you."

_'The ship rescued us, and now the Doctor's talking to it,'_ Donna thought. _'My concept of 'possible' and 'normal' will never be the same again. Not that it has been since I met him.'_

But nonetheless, she put her hand on the nearest column and expressed an unspoken thanks to the TARDIS, on her way to the doors to look outside.

"Is it safe to go out?"

"Maybe. That one trap's gone, but there could be others."

"Yeah, probably. Shame. I wanted to have a proper look around."

"Might be best to save that for another time. We could go through the proper channels, make a day of it?"

Donna accepted that, given their experiences that day, that was probably the best idea and closed the doors.

"Have you got a DVD player? If we can't wander alien ruins, then it's about time you saw Indiana Jones!"

Donna grinned, and the Doctor sighed. This was something she clearly wasn't going to give up on.

"Or we could go find another planet to explore?" he said. "One without multi-dimensional booby traps?"

"Oh, go on then!"

He threw the lever, and off they went.

/

**Author's Note:**

> Has there ever been an Indiana Jones reference in Dr Who? I can't remember one, so I'm hoping there isn't, otherwise I'll just pretend the Doctor momentarily forgot him. (I originally removed the references to Indiana Jones from the competition entry in case that went against copyright, but a "anything you recognise isn't mine" disclaimer should be enough here).


End file.
